https://zenhax.com/viewtopic.php?t=27
It starts with 0x78 (rarely also with 0x58).
Use offzip to test if it's really zlib.
Code:
78 da ed 8f 6b 48 53 61 1c c6 df 65 35 ed 32 8d x...kHSa...e5.2.
4a 49 9d 65 20 88 93 2d 13 ba a0 53 ab 85 5a b9 JI.e ..-...S..Z.
96 49 a2 76 d0 32 d7 cd a8 b9 72 a9 1d 2d fd 60 .I.v.2....r..-.`
65 84 a5 cd 4a 26 eb 2a 76 d9 64 5e 32 87 a7 bc e...J&.*v.d^2...